Pneumatic separator for pulverizing mills



March 24, 1 3 w. MCLAUGHLIN ET AL PNEUMATIC SEPARATOR FOR PULVERIZING MILLS Filed Dec. 19, 1927 awn 11oz L MiI -JUGHLIN LAUGHLIN,

abbo'cmq Patented Mar. 24, 1931 UNITED STATES PATENT OFFlE WILSON L. MCLAUGHLIN AND HERROLD L. MCLAUGHLIN, F DES MOINES, IOWA PNEUMATIC SEPARATOR FOR PULVERIZING MILLS I I Application filed December 19, 1927. Serial No. 241,200.

The principal object of this invention is to tion of the device correctly mounted in the provide an eilicient device to be used .in conreceiving chamber. nection with a pulverizingmill for pneumati- F 3 is a perspective view of the trough cally separating the coarser particles from portion of the separator and more fully il- 1 the fine material and returning the former lustrates its construction. i to the pulverizing chamber of the mill. Machines for the pulverizing of material More specifically, the object of this invensuch as coal and the like, use a current of air tion is to provide a pneumatic separator for to remove from the machine the particles that pulverizing mills comprising, a receiving have been finely ground in the pulverizing chamber communicating with the pulverizing chamber. This current of air leads to a sepachamber of the mill, a trough in the receivrator either of the bag or centrifugal type ing chamber so placed and positioned that the for removing the comminuted material from material impregnated air must pass around the air. However, if one inspects the mateand over the same, and return pipes communirial obtained by the separators, it will be 15 eating with the bottom of the trough and the found that much coarse matter that should inside of the mill pulverizing chamber. never have left the pulverizing' mill exists in A further object of this invention is to pro the finely ground material. This is objecvide an apparatus for separating coarse par tionable and it is the purpose'of our separator ticles from fine material, which is of such to prevent this coarse material from entering 20 form and construction that the granular mathe fabric or centrifugal separator. terial pneumatically induced from a pulver- We have designated the ordinary pulverizing mill is caused to be divided and again to i hg chamber of a mill by the numeral 10, meet directly over a horizontal trough Which consists of a plurality of side plates thereb p rmittin th coarser particle to secured together by suitable means. In the settle in the trough by the action of the two P 1 1 Port-i011 Of this Chamber is the 1 streams coming together above a calm that mg 11 for the inserting of material in the exists slightly below the contact points of the p v i i g ch mber. Rotatably mounted in two streams of mat rial lad ai two sides of the pulverizing chamber 10 is A still further object is to provide a sepaa shaft 12 upon which is permanently se- 30 rator for separating coarse particles fro cured the cylinder 13 having the pulverizing fine material laden air or gas that is capable hammers 14. The shaft 12 isdesigned to be of obtaining the desired coarseness of mateo ed in the ordinary manner by a prime 1 1 f th i or gas mover (not shown). The numeral 15 desig- A still further object of this invention is to Rates 1 receiving chamber secured in the up- 35 provid a separator that i co omi al in per forward portion or" the pulverizing chammanufacture and durable in use her and communicating with the same, At These and other objects will be apparent to h top and near he Center of thlsrecelv ng those skilled in th art, chamber is an outlet pipe 16 communicating Our invention consists in the construction, with an induction fan 17, shown in convenarrangement and combination of the various 131011211 form 111 g- 1 and cleslgned to be parts of the device wh r by th obj t @011- tated by the electric motor 18 The numeral templated are attained as hereinafter more l 9 le lgn es an o tl t p1pe irom the inducfully set forth, pointed out in our claims and t1011 fan orchnary f bric or centrifugal illustrated in the accompanying drawing, in Separator (not shown). Mounted 1n the rewhi h; ceiving chamber 15, extending the full length 1 i a id ti l i f our of the same and directly under the outlet pipe plete device mounted on a pulverizing mill 16 IS h o g 2 T n ral 21 slgand ready for use. nates return lead pipes, each having one of Fig. 2 is a top plan sectional view taken on their ends communicating with the bottom of ine 22 of Fig. l and shows the trough porthe trough 20 and their other ends terminate.

Mounted in the pipe 16 is a. gate valve 24' for limiting the amount or air drawn through the pipe 16 by the fan 17.

lbs practical operation of the device is as follows: The mater al 25 1s placed in the pulverizing chamber through the opening ll where the rotating hammers l l eventually reduce it to a pulverized state. It the elec tric motor 18 is rotating the fan 17. a current of air will be drawn through the pipe 22, through the pulverizing chamber, through the receiving chamber 10, and forced into the fabric or centrifugal separator, not shown. This current oi air passing through the pulverizing chamber will naturally gather with it, the material. in the pulverizing chamber that has been reduced to impalpability. This air also catches coarser particles and carries the same from the pulverizing chamber before they are reduced to comminuted state. However, due to the construction and placement of the trough 20, the material impregnated air is caused to divide and pass on each side of the trough, as shown in Fig. 1. As the outlet pipe 16 is directly above the trough 20, the two streams of air must come in direct contact with each other over the trough 20; the heavier particles striking each other and falling into the trough 20 where they pass through the pipes 21, back into the pulverizing chamber. By the opening or partially closing or" the gate valve 2%, the material laden air passing through the pipe 16 will be proportionately regulated. It the gate is partially closed, the force of air passing around and over the trough 20 will be greatly reduced and the more finer of the coarser particles carried by the air will drop into the trough. In other words, any degree 0t fineness of the particles desired to be returned to the Vpulverizing chamber may be realized by the adjusting of the valve 24;. Also, it will be found that still air exists in and slightly above the trough and the heavier particles,

which are naturally at the bottom of each current of air, readily experiences this still air which cannot support it and they descend into the trough 20.

From the foregoing, it will readily be un-- derstood by those skilled in the artthat we have provided an apparatus that will eliminate the undesirable coarse material from a pulverizing device from reaching the fabric or centrifugal separator.

Some changes may be made in the construction and arrangement of our improved pneumatic separator without departing from the real spirit and purpose of our invention and it is our intention to cover by our claims any modified forms of structure or use of mechanical equivalents which may be reasonably included within their scope.

We claim:

1. In a device of the class described, a receiving chamber having an inlet and an outlet opening, a means for passing a current of air through said chamber, a trough so positioned in said receiving chamber that the current of air passing through the receiving chamber must divide into two streams and again joint into one stream directly above the said trough, and pipes having one end communicating wi h the inside of said trough, extending downwardly in said receiving chamher and terminating at a point at the side of the main current of air passing through said chamber.

2. In a device of the class described, a receiving chamber having an inlet opening in its bottom, an outlet pipe communicating with the top of said receiving chamber, a means for drawing a current of air through said re ceiving chamber and outlet 1 pipe, a valve in said outlet pipe for restricting its opening, a trough in said receiving chamber and directly below said outlet pipe, and a pipe communicating with the inside and bottom of said trough, extending downwardly in said receiving chamber and terminating of the point to the side of the main column of air passing through said chamber.

3. In a device of the class described, a housing having an inlet opening in its bottom portion, an outlet pipe communicating with the inside of said housing at a point near its top, a means for passing a current of material impregnated air through said housing, a trough pointed at its bottom in the path of said upwardly passing current oI material impregnated air capable of dividing said current into two distinct streams, and a pipe leading downwardly and outwardly from said trough for obtaining the material collected by said trough and depositing the same to the side of the main current of material impregnated air passing through said housmg.

4. In a device of the class described, a housing having an inlet opening in its bottom and an outlet opening in its top, a means for passing the current of material impregnated air up through said housing, and an elongated troughextending from two sides of said housing and in the path of the current of said material impregnated air for dividing the same into two distinct streams and allowing them to meet and strikeeach other directly over its open top, and a pipe leading from said trough for obtaining the material collected by said trough and depositing the same at one side of the current of material impregnated air through said housing.

5. In a device of the class described, a separator housing having an inlet opening, an outlet pipe communicating with the inside of said separator housing at a point in its top portion, a means for passing the current of material impregnated air through said separator housing, a material receiving trough pointed at its bottom for dividing said current of material impregnated air into two distinct streams and allowing them to meet again directly above its open top; said trough having its upper marginal edges considerably lower than the lower marginal edge of said outlet pipe, and a pipe having one end communicating with the inside of said trough, extending downwardly and to one side of said separator housing and terminating at a point outside the main current of the material impregnated air.

WVILSON L. MCLAUGHLIN. HERROLD L. MoLAUGHLIN.

passing upwardly 

